U.S. stocks followed European and Asian markets into the red on Monday after Greece announced it will miss deficit reduction targets worked out in a bailout deal with lenders. Despite a series of austerity measures, the Greek government projects its deficit at 8.5 percent of the country's economic output, well above the 7.6 percent target it had promised international creditors. The admission renews fears that Greece may not get the crucial assistance it needs to avoid default.

The possibility that Greece will not make good on its debts moved a step closer to reality on Monday. At a eurozone finance ministers meeting in Luxembourg, EU Monetary Affairs Commissioner Olli Rehn said Greece and the 17 nations that use the euro have reached a critical juncture.

"It seems that Greece is likely to miss the target this year, next year and concrete measures agreed to so far are going a long way to meet all the fiscal targets," said Rehn. "As I said, it is essential now that we will assess the measures, we will review the figures."

Greece's next bailout installment - about $11 billion - is predicated on the country's ability to reduce spending - spending that has raised the country's debt load to a staggering 173 percent of national income. Without the next installment, Greece is expected to run out of money in a matter of weeks.

David Jones is a market strategist at IG index:

"The concern is that there's an awful lot of talk from politicians and central banks to an extent and very little in the way of immediate action," said Jones. "So I think the worry is that once again this latest problem will extend just how long this takes to try to solve."

Greece has imposed a series of unpopular austerity measures that have led to almost daily protests from workers weary of deep pay cuts and higher taxes.But Nikos Christodoulou at Merit Securities says it is no secret why Greece has been unable to reach its target goals.

"The main reason is the recession," said Christodoulou. "The recession widens in Greece at this moment. We know that it will be at least 5.5 percent for this year and we may have a new recession in the next year. So the bigger the recession, the higher the budget deficit."

Some analysts accuse the European Union, the IMF and the European central bank of creating unnecessary drama. Even so, Oliver Roth at Close Brothers Seydler Bank says it's unlikely the so-called "Troika" will allow Greece to fail.

"For me, it is clear that the Troika will pay sooner or later the credits to Greece and therefore I don't think there is a reason for being so negative," said Roth.

Experts say pulling the plug on Greece could have massive repercussions in Europe, especially to French banks with heavy exposure to Greek debt. Some say the resulting crisis could plunge the global economy into another painful recession.